Catadioptric optical system and exposure apparatus having the same

Abstract

A projection exposure lens system has an object side catadioptric system, and intermediate image and a refractive lens system. The refractive lens system from its intermediate image side and in the direction of its image plane has a first lens group of positive refractive power, a second lens group of negative refractive power, a third lens group of positive refractive power, a fourth lens group of negative refractive power, and a fifth lens group of positive refractive power.

We claim:  
     
       1. Projection exposure lens system with an object side catadioptric system, an intermediate image and a subsequent refractive lens system, characterized in that the refractive lens system from the intermediate image side on has: 
       a first lens group of positive refractive power,  
       a second lens group of negative refractive power,  
       a third lens group of positive refractive power,  
       a fourth lens group of negative refractive power, and  
       a fifth lens group of positive refractive power.  
     
     
       2. A projection exposure lens system according to  claim 1  comprising: 
       an object side catadioptric system,  
       an intermediate image, and  
       a refractive lens system,  
       in which said refractive lens system comprises a field lens group, an intermediate correcting lens group and a focusing lens group. 
     
     
       3. A projection exposure lens system according to  claim 1  comprising: 
       an object side catadioptric system,  
       an intermediate image, and  
       a refractive lens system,  
       in which said catadioptric system has an imaging ratio of greater than 0.95, and different from unity. 
     
     
       4. The projection exposure lens system according to  claim 1 , in which at least one −+ power doublet is arranged next to a system aperture. 
     
     
       5. The projection exposure lens system according to  claim 1 , comprising lenses made of at least a first material and lenses made of a second lens material in which no more than one lens of said catadioptric system is made of said second lens material. 
     
     
       6. The projection exposure lens system according to  claim 5 , in which the diameter of lenses made of said second lens material does not exceed the 0.85 fold of the diameter of a biggest optical element. 
     
     
       7. The projection exposure lens system according to  claim 5 , in which the diameter of lenses made of said second lens material does not exceed 220 mm. 
     
     
       8. The projection exposure lens system according to  claim 1 , in which said catadioptric system contains no more than six lenses. 
     
     
       9. The projection exposure lens system according to  claim 1 , in which said catadioptric system contains no more than five lenses. 
     
     
       10. The projection exposure lens system according to  claim 1 , in which the longitudinal chromatic aberration is less than 0.015 μm per a band width of 1 pm at 193 nm. 
     
     
       11. The projection exposure lens system according to  claim 1 , in which longitudinal chromatic aberration is less than 0.05 μm per a band width of 1 pm at 157 nm. 
     
     
       12. The projection exposure lens system according to  claim 1 , in which the imaging ratio of said catadioptric system is greater than 0.8. 
     
     
       13. The projection exposure lens system according to  claim 1 , in which said projection exposure lens system is both side telecentric. 
     
     
       14. The projection exposure lens system according to  claim 1 , having at least one beam waist in a refracting subsystem, and at least one −+ power doublet is arranged behind a last beam waist. 
     
     
       15. The projection exposure lens system according to  claim 1 , in which at least one −+ doublet is arranged such that a light beam diameter inside lens elements of said −+ doublets is more than 80% of a maximum beam diameter. 
     
     
       16. The projection exposure lens system according to  claim 1 , further comprising a concave mirror in said catadioptric system and a reflecting prism inserted for reflection of a light beam between an object and said concave mirror. 
     
     
       17. The projection exposure lens system according to  claim 1 , comprising lenses made of a first lens material and lenses made of a second lens material in which said projection exposure lens system is designed for use with one of 248 nm and 193 nm light and said first material comprises fused silica and said second material comprises calcium fluoride. 
     
     
       18. The projection exposure lens system according to  claim 1 , comprising lenses made of a first lens material and a second lens made of a second lens material in which said first material comprises calcium fluoride. 
     
     
       19. The projection exposure lens system according to  claim 1 , further comprising a first deflecting element in said catadioptric system, in which exactly one lens is placed between an object and said first deflecting element. 
     
     
       20. The projection exposure lens system according to  claim 19 , in which the ratio of focal length of said one lens before said first deflecting element over the distance from said one lens to said first deflecting element is unity within (±) fifteen percent.